Have a strange issue with the bike lacking some top end power. Pulls well through the revs until I hit top gear and then just flattens out. Won’t pull past 140kph. Will pull hard in 4th up to 140 but in top it’s got no guts. This is intermittent and when it comes right it will do 160 like it should though still a bit slow finding it’s top end.
Any suggestions?
Hi there they only good to 160ks sounds like a gearing to me?
Yeah I know it’s top speed is 160 but when it’s faulty it won’t pull past 140. Maybe struggle slowly to 150. And struggles at 120 with a little bit of hill.
I’m wondering about the electrical switch on the carby which I’ve been told affects the advance or retard at full throttle.
Its been shown on A dyno that the carb switch makes no noticeable difference connected or disconnected, and on bikes where a different carb is fitted it’s not used at all with no obvious effect on performance.
My best guess at this stage is some weird scenario where your fuel hose is getting crimped at high speed restricting fuel delivery. That still sounds far fetched to me though.
Interesting. Thanks for that information. I have been suspicious of my vacuum fuel tap as it has been playing up. I’m going to swap it out for a petcock type.
Hi there i got rid of my vacuum fuel tap had a fault it kept cutting out?its all good now i put a peacock tap on it now
Yes when I first started having trouble I was running out of fuel and engine would stop but then start again. Pulled the tap apart a couple times. Looked ok but second time I noticed the diaphragm seemed to be sticking. Cleaned and lubricated with petroleum jelly. Hasn’t cut out again but I don’t trust it. Maybe still not letting enough fuel through.
Reco kit for tap, $50. New tap $130. Petcock off trademe $30.
Tomorrows job.
Did it fix it?
Haven’t had a chance to ride it yet. Riding from Nelson to Auckland and back this week so I hope so.
Meanwhile fitted a cycleworx muffler and opened the airbox. Have also eliminated the kill switch on the handle bars. That was pretty shitty. Running a lot better but still wasn’t happy at the top end so hopefully the tap does it otherwise back to chasing electrical faults I guess.